It is already known, particularly in connection with goods-carrying vehicles, to provide at the rear of the vehicle (which may for example be a truck of the trailer of a tractor/ trailer combination) a detector which, when the vehicle reverses, detects an obstruction and serves to generate a signal which can be used to initiate application of the vehicle's brakes so bringing the vehicle to a standstill and minimizing the risk of damage or injury to any obstruction or person behind the vehicle.
There are several types of such detectors available, and at least one known system is interrelated to a driver-controlled reverse gear selector on the vehicle in such a manner that the system is armed or made ready for brake application to be effected upon receiving a signal from the detector only when the vehicle's driver has selected reverse gear. Thus with this system a signal generated by the detector causes brake application only when the vehicle's driver has deliberately operated the selector for the vehicle to be driven backwards.
There are other methods which necessitate the engaging of an electrical switch, or the operating of a camera and associated equipment, and rely on the driver to control or activate. None of these will operate automatically if for instance the vehicle should commence running backwards, e.g. down a hill when out of gear, or as a result of being impacted at the front. Thus the prior proposed systems do not safeguard against the risk of accident in the event of unintentional reverse movement of the vehicle, which can arise in a substantial number of varied circumstances of which possible the most important one is the risk arising from inattentive parking upon an inclined surface.
An object of the present invention is to provide a braking system with safeguards against any movement of a vehicle, whether intentional or unintentional, and in which the need for operation of an electrical switch or a gear selector of the vehicle is obviated.